When we bought our new pool we did have to get our electric to new NEC codes for the pool but our last pool was installed 20+ years ago and the code changed. As far as sand as long as it's in good/great condition you're probably be fine. We needed more sand because our pool was gone for 3 years and the sand started growing weeds and the rocks that were around the pool migrated into the sand. We did have to clear out the old rocks for the installers to install the new pool. Word of advice if you have rocks and need to remove them - do it while the old pool wall is up as it makes it easier to not get rocks onto the sand area. I sifted my old sand to get rid of the weeds and rocks before they put down the new sand and installed the pool.
